I understand that we need to create MXML file to define a view. Suppose on user click of a button I want to show another view defined in another MXML file. How can I do this?
Apache – Adobe Flex – How to jump view
apache-flexflex3
Related Solutions
Your Actionscript class needs a reference to the display list in order to add your component to the stage. MXML is simply declarative actionscript, so there is no difference between creating your instance in Actionscript or using the MXML notation.
your function:
static public function logout():void {
var startPage:StartSplashPage = new StartSplashPage();
}
could be changed to:
static public function logout():StartSplashPage {
return new StartSplashPage();
}
or:
static public function logout():void {
var startPage:StartSplashPage = new StartSplashPage();
myReferenceToDisplayListObject.addChild( startPage );
}
If your actionscript does not have a reference to the display list, than you cannot add the custom component to the display list. Adding an MXML based custom component is no different than adding ANY other DisplayObject to the display list:
var mySprite:Sprite = new Sprite();
addChild(mySprite)
is the same as:
var startPage:StartSplashPage = new StartSplashPage();
myReferenceToDisplayListObject.addChild( startPage );
Both the Sprite and the StartSplashPage are extensions of DisplayObject at their core.
You reference MVC in the comments to another answer. Without knowing the specific framework you've implemented, or providing us with more code in terms of the context you are trying to perform this action in, it is difficult to give a more specific answer.
Tracking it down
At first I thought this was a coercion bug where null
was getting coerced to "null"
and a test of "null" == null
was passing. It's not. I was close, but so very, very wrong. Sorry about that!
I've since done lots of fiddling on wonderfl.net and tracing through the code in mx.rpc.xml.*
. At line 1795 of XMLEncoder
(in the 3.5 source), in setValue
, all of the XMLEncoding boils down to
currentChild.appendChild(xmlSpecialCharsFilter(Object(value)));
which is essentially the same as:
currentChild.appendChild("null");
This code, according to my original fiddle, returns an empty XML element. But why?
Cause
According to commenter Justin Mclean on bug report FLEX-33664, the following is the culprit (see last two tests in my fiddle which verify this):
var thisIsNotNull:XML = <root>null</root>;
if(thisIsNotNull == null){
// always branches here, as (thisIsNotNull == null) strangely returns true
// despite the fact that thisIsNotNull is a valid instance of type XML
}
When currentChild.appendChild
is passed the string "null"
, it first converts it to a root XML element with text null
, and then tests that element against the null literal. This is a weak equality test, so either the XML containing null is coerced to the null type, or the null type is coerced to a root xml element containing the string "null", and the test passes where it arguably should fail. One fix might be to always use strict equality tests when checking XML (or anything, really) for "nullness."
Solution
The only reasonable workaround I can think of, short of fixing this bug in every damn version of ActionScript, is to test fields for "null" and escape them as CDATA values.CDATA values are the most appropriate way to mutate an entire text value that would otherwise cause encoding/decoding problems. Hex encoding, for instance, is meant for individual characters. CDATA values are preferred when you're escaping the entire text of an element. The biggest reason for this is that it maintains human readability.
Best Answer
You could use a viewstack. each item in the viewstack would be a different MXML file so when the user clicks a button you change the selected index of the viewstack which makes the view change.
You could probably do with checking out the examples in http://www.adobe.com/devnet/flex/tourdeflex/ this will help explain so much more than a simple answer will. From your question it sounds like you need to get the basics of flex first and the tour de flex app contains loads of examples with source code. HTH.